The present invention relates to an apparatus to aid in the aligning of paper in typewriters and similar machines so that a keystroke will fall within a desired space on a sheet of paper. It often happens that paper in a typewriter will slip out of alignment with previous lines during erasures or when it is removed and reinserted in the machine. It is then desired that both letter and line space be restored to the original so that additions and corrections will coincide accurately with the previous material. In many cases typing is done on printed forms having boxes to check or preprinted lines on which to enter replies to questions. The adjustment of the paper is awkward and often requires several attempts because the line guide provided for this purpose is interrupted by an aperture at the exact point where alignment is needed. The aperture is necessary because space must be provided for the type face to strike the paper.
This problem was recognized early in the development of typewriters and prior art teaches some of the methods devised for overcoming it. In Nicely (U.S. Pat. No. 2,588,147), for example, a three hole plate is mounted so that it can swing over the aperture. When the two outside holes are aligned with previously typed letters, the central hole will now indicate where the key will strike. The carriage and line spacers are released and the paper moved so that the central hole is over the area on which the correction is to start. The plate is now swung away, the spacers returned to normal and the work resumed. In an earlier patent, Baron (U.S. Pat. No. 1,023,796) uses a flexible wire to partially bridge the aperture and to point down to the striking space of any key. When the paper is adjusted so that the spot pointed to by the end of the wire is aligned with an existing letter, the paper can then be moved to the desired open area. The flexible wire encounters part of the key bar during the end of the stroke, bends and then acts as a repulsing spring to return the key bar to its rest position. Other mechanical devices for alignment are described in Dobson (U.S. Pat. No. 1,582,906) and Foothorap (U.S. Pat. No. 1,383,096).
Although all of these devices are applicable to the problem of alignment, none is convenient or rapidly carried out.
Another problem which commonly occurs in typing is that of the margin signal. The presently used bell is often ignored by some typists which then leads to uneven right hand margins.
It is a first objective of the present invention to provide a non-contacting, readily adjusted and easily used line and column alignment device to permit corrections and additions to be made to existing typing and facilitate typing on preprinted forms.
It is a second objective of the present invention to permit alignment in computer printers as well as typewriters.
It is a third objective of the present invention to reinforce presently used margin signals to better gain the typist's attention.